Billionaire investor, who gained increasing fame in recent months due to his attempted take over of Dell, has announced via Twitter that his firm has taken a “large position” in Apple:

We currently have a large position in APPLE. We believe the company to be extremely undervalued. Spoke to Tim Cook today. More to come.

— Carl Icahn (@Carl_C_Icahn) August 13, 2013

Icahn further added that he had a “nice conversation” today with Apple CEO Tim Cook. Icahn suggested even larger buy-back plans for Apple. Earlier this year, Apple launched a major multi-billion-dollar stock buy-back program.

Had a nice conversation with Tim Cook today. Discussed my opinion that a larger buyback should be done now. We plan to speak again shortly.

Responding to the news, AAPL investors helped the stock sore to a new 6 month high of over $488 per share. Apple has also responded to the news:

Additional notable tweets from around the web:

Icahn’s stake in Apple said to be more than $1 billion, with Icahn projecting shares will rise above $600, via @BloombergNews

— Sarah Frier (@sarahfrier) August 13, 2013

.@Carl_C_Icahn to CNBC: Large buyback is no a brainer for Apple; would enhance stock value tremendously. $AAPL

— CNBC (@CNBC) August 13, 2013